The couple bought the five-bedroom, six-bathroom home on 3.76 hectares at 149 The Manse Rd, Myocum, for $5.09 million last March and settled in both their names in May.

But the stunning property, once known as the "King of the Hill", was last night spotted on realestate.com.au by Will Phillips and Peter Randall of McGrath Byron Bay, with sources saying it had a guide price of $4.5 million.

At the time of going to press, the two agents could not be reached to discuss the reasons for the sale. However, the buzz in town is that Cooper and Marsh have had a tumultuous 26-year relationship and have finally decided to call it quits.

The move to Byron Bay was a huge change for the couple, who moved from Tamarama.

In February last year, they sold their last house with an eight-person lift and heated pool at 29 Carlisle Street to Adrian Fonseca, vice-chairman of AFL team GWS Giants, for A$11.05 million.

Their stunning three-storey home offers 500 square metres of floor space and has been hailed as a 'once in a lifetime' opportunity.

The hinterland estate has views of Julian's Rock and the majestic Werning Mountains.

There is an outdoor entertaining area and manicured lawns surrounding the 15 metre swimming pool.

The opulent interior includes a magnificent living and dining area with an EcoSmart fireplace leading out to a wrap-around terrace.

The master suite occupies the entire third floor and has a walk-in cloakroom, terrace, en-suite with bath and sea views.

There is also a media room, wine cellar, games room and three car garage.

The grounds are described as a stunning botanical garden with a network of pathways throughout.

Other attractions include a chalet/gazebo, idyllic dam, basalt boulder formations and a 180m2 barn/shed.